Balancing machine



April 25, 1939. c, c, cADDEN 2,155,528

BALANCING MACHINE Filed July 3, 1935 5 Sheets-Sheet 1 April 1939- c. c. CADDEN 2,155,528

BALANCING MACHINE Filed July 3, 1935 5 Sheets-Sheet 2 April .25, 1939. c. c CADDEN BALANCING MACHINE Filed July 3, 1955 5 Sheets-Sheet 3 BMW April 25, 1939. c. c. CADDEN BALANCING MACHINE Filed July 3, 1935 5 Sheets-Sheet 4 [ha /Es ["5500527 Ikl April 25, 1939. c. c. CADDEN BALANCING MACHINE Filed July 3, 1935 5 Sheets-Sheet 5 Ill/II IIII ' HL ETfiibE ,ZhEE/EE [1 5555517 j Patented Apr. 25, 1 939 2,155,528 BALANCING moms:

Charles C. Cadden, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application July 3, 1935, Serial No. 29,867

16 Claims.

This invention relates to apparatus for determining the balance of annular objects and is especially useful in determining the balance of pneumatic tires. I

The principal objects are to provide accuracy and efilciency in the determination of the characteristics of unbalanced forces, to provide for marking the position where mass must be added to balance the object, and to provide for automatic marking of the object at such location with the amount of the mass to be added.

Other objects will appear from the following description and the accompanying drawings.

Of the drawings:

Fig. 1 is a side elevation of the machine in its preferred form with a pneumatic tire casing thereon, parts of the tire and the machine being broken away.

Fig. 2 is a similar view of the opposite side of the machine.

Fig. 3 is a sectional detail view taken on line 3-3 of Fig. 2, parts being broken away.

Fig. 4 is a detail sectional view of one of the printing elements and its actuating mechanism, parts being broken away.

Fig. 5 is a sectional detail view taken on line 5-5 of Fig. 3, showing the construction of the printing selector mechanism, parts being broken away.

Fig. 6 is a detail sectional view taken on line 6-5 of Fig. 2, showing one of the knife edges and the beam construction.

Fig. 7 is a sectional elevation taken on line 1-1 of Fig. 2, parts being broken away.

Fig. 8 is a similar sectional view, taken on line 8-8 of Fig. 2, parts being broken away.

Fig. 9 is a diagram showing the air piping and associated mechanism.

Fig. 10 is a wiring diagram showing the electrical circuit and its controlling contact members.

Fig. 11 is a detail sectional elevation taken on line H-ll of Fig. 9, showing the construction of one of the valves, parts being broken away.

Fig. 12 is a similar sectional view taken on line l2-l2 of Fi 9.

Fig. 13 is a sectional detail view of the valve block which controls selection of the marking plungers.

Referring to the drawings, the machine in its preferred form. comprises a pedestal H] which supports a horizontally disposed plate H, secured thereto by bolts l2. A pair of brackets l3, l3 secured to the plate I I at its extremities supports a pair of parallel, horizontally disposed rails l4, M. A pair of V-blocks l5, I5 are mounted upon the rails u, w with their V-surfaces in alignment. Suitable adjusting means are provided for aligning these bearing surfaces.

The beam which supports the tire to be balanced is constructed so as to permit rotation of g the tire and is preferably made as follows:

A pair-of horizontally disposed rails l6, 16' are connected together in parallel spaced relation by tie-members H, II, to which blocks l8, l8 are secured for adjustment laterally of the beam by 10 screws i9, (see Fig. 6) which passthrough slots in the tie members. Adjusting screws 20, passing through the rails l8, l6, and bearing against the blocks l8, provide lateral adjusting means.

A pair of hardened knife edges 2|, 2| are held 16 in vertical slots in the blocks It by screws 22 and may be vertically adjusted in said slots by means of set screws 23. A spindle 24 is fixed to the beam at the front of the machine in vertical alignment with the knife edges and preferably with its axis coincident with said knife edges. A chuck 25 for centering and supporting the annular object to be balanced is mounted in antifriction ball-bearings 26, 21 carried by the spindle.

To provide for rotating the object on its axis, an electric motor 28 is fixed to the beam. It carries a pulley 29, which, through a belt 30, drives a pulley 3| fixed to one spindle of a speed reducing unit 32, of the worm gear type. The 30 other spindle of the speed reducer is frictionally connected'by a length of rubber tubing 33 to a shaft 34 journaled in a bearing 35 supported by the beam. Shaft 34 has fixed thereon a pinion 36 which meshes with a gear 31 carried by the 35 chuck 25. The leads (not shown) to the motor 28 are made of flexible wire, or the terminals of the motor may dip in mercury wells to avoid friction.

While rotationof an off-balance tire or other 0 annular object will cause the beam to oscillate and indicate off balance even with the axis of the annular object above or below the line passing through the knife edges as long as the axis is vertically in alignment with the knife edges, it has been found that when the axis of rotation of the object is coincident with the knife edges, the amount of deflection of the beam. will be in exact proportion with the amount of ofl-balance of the object. gii,

To provide for the testing of annular objects of different sizes, the chuck 25 may be formed with a series of concentric seating portions 25a,

In order to indicate the deflection of the beam,

the beam is equipped with a sheet metal sector 38 fixed thereto and having graduations 88 engraved on its face. A stationary frame, sup- .a tape supporting face amuate in shape and struck from-the knife edges as a center, so that the moment exerted by the weight 45 is always constant.

Tape 48, which. supports weight 48, is similarly attached to a segmental drum 50, attached to the beam, but this drum surface follows an Archimedean spiral so that when the beam is at zero position the moment exerted by weight 46 is equal to that exerted by weight 45, but when the sector 38 swings to the left (see Fig. 7) the mo ment due to the weight 88 is gradually increased and when it swings to the right is gradually reduced by an equal increment for each degree of beam deflection. To provide for further damping of the vibration of the beam the weight 46 is suspended in a cistern filled with machine oil or other liquid. The liquid not only frictionally damps the vertical movement of the weight, but effectually prevents lateral swinging of the weight due to change in the leverage. As the weights .5 and 48, when the beam is at zero position, have the same radial disposition from the knife edges, weight 48 is so proportioned that its weight minus its buoyancy equals the weight of the weight 45. I

In order to prevent injury to the knife edges, and to prevent shifting of the beam when an article to be balanced is placed on the device, beam-arrest is provided as follows: A pair of plates 52, 52', having arcuate upper edges, whose center of curvature is at the line passing through the knife edges, are fixed to the beam in position to engage V-blocks 58, 58', supported by rails II, It, when the beam is raised. A block 54, fixed to the beam, is formed on its lower side with an arcuate grooved surface of V-shaped cross-section. A jack-screw 55 is slidably journaled in a stationary sleeve 56, fixed to the rails ,14' below the block 54, and has a pointed end adapted to enter the V-groove therein and raise the beam from the knife edge bear ings when the screw is elevated. An internally threaded pinion 51 engages the threaded jackscrew and is engaged by a rack bar 58. An air cylinder 58, of the double acting type is mounted on plate l8 and is provided with a piston and piston rod 80 to which rack 58 is attached. When air is admitted to one end of the cylinder 59 the jack screw 55 is raised and, engaging the block 54,

raises the beam from its bearings. When air is admitted to the opposite end of the cylinder the Jack is lowered, releasing the beam. It may be noted that the chuck 25 may be rotated continuously, independent of the beam-arrest mechanism. As the chuck is rotated at a very slow velocity (about 6 R. P. M.) articles may be placed on the device and taken oil, without stopping the rotation of the motor. This is important, as accurate results are obtained with constant speed of rotation and stopping and starting of the motor would not be conducive to accurate results.

While the deviceas Just described may be used successfully, additional advantages may be obtained by additional mechanism whereby the operation of the device is made more or less automatic. Such additional mechanism may include means for automatically arresting the beam 5 at its point of maximum oscillation and means for automatically marking the light side of the tire or other annular object, including means for automatically marking at such position on the object t amount necessary to be added to such 10 position 0 balance the object.

These mechanisms are preferably operated by compressed air and the beam arrest just described is utilized not only to arrest the beam when placing an object to be balanced on the device, but also to arrest the beam at its position of maximum deflection.

To operate the beam arrest and also to supply air under compression to the other mechanisms a Ross valve 6| such as is illustrated and described in U. S. Letters Patent of Rosa. No. 1,486,303 is mounted on the base of the machine. This valve comprises a casing on which is pivotally mounted, as at 62, a lever 63. This lever controls the positions of four poppet valves, 64, 65, 86, 61, which are normally spring-pressed against seats formed in the valve. The valve Si is provided with an exhaust port 68 and a compressed air supply pipe 89, and air pipes 10 and H leading therefrom to opposite ends of cylinder 59. The valves are so connected that when lever 83 is in the position shown in Figs. 1, 2, 10, l1, and 12,-with the pedal 63 depressed, air from the supply line may pass through pipe 18 and pipe II is connected to the exhaust 68, thereby causing I the rack 58 to move to the right (Fig. 9) and releasing the beam. When lever 83 is moved in the opposite direction, as hereinafter described, pipe I0 is connected to the exhaust 88, and pipe 1] to the supply 69 and the beam is arrested. 40

A compression coil spring I2, mounted in a spring barrel 1!, normally holds the lever 83 with its pedal 63" in raised position. A latch 14, urged by a tension spring 15, carries a roller 16 adapted to engage under the lever 83 in its depressed position and to hold it in such position while the beam is oscillating. A solenoid 11 is adapted when energized, as hereinafter described, to withdraw roller 18 and thereby release lever 63 whereupon, under influence of spring 12, the valve lever v 63 is reversed to cause arrest of the beam.

In order to accomplish release of the lever 53 at the point of maximum deflection, regardless of the location of the heavy point on the object when the machine is started, the following mechanism 55 is provided: Three circuit closing members 18, I9, and 88, are all arranged in series in the same circuit with the solenoid 11. (See Fig. 10.) Circuit closers 18 and 19 are pivotally mounted on bar 42 near the graduated sector 38, and are of the 0 mercury tube type. They are pivoted at 18' and 19" respectively and are provided with depending actuating arms 18 and 19''.

Circuit closer I8 is balanced upon its pivot so as to stay in any position to which it is tipped. 5 Circuit closer i9 is weighted, as at 19, so as to normally close its contacts. A pin 38, mounted on the rim of sector 88, is adapted to contact with arms [8 and 19 and rock the circuit closers on their pivots as it contacts with them. A small air cylinder 8| is located above circuit closer l8 and encloses a. piston plunger 82, adapted to be projected against circuit closer 'l8,' to set it in open position, and a coil spring 83 to retract the plunger. An air supply pipe 84 connects the cylinder II to the pipe 1-I so that when the beam is arrested the circuit closer "is automatically set at open position but when the beam is set on its knife edges the circuit closer is free to rock on its pivot.

Circuit closer 30 is normally open and comprises a closed cylinder 35 in which a float is suspended above a pair of contacts 30, 31, by an insulating 'iluid, such as oil. An adjusting screw 00 limits movement of the float. A pair of conduits 00, 30 connect the top and bottom, respectively of the float chamber to the bottom and top, respectively, of a vertical cylinder 3|. A piston 82 on a rod 33 causes the oil to circulate through pipes 33, 00 at each deflection of the beam, the oil flow in one direction (when the beam sector swings to the right in Fig. 7) causing the float to close the contacts 00, 31.

In order to actuate the rod 33 an arm 94, on the beam, has anarcuate surface 34*. Inextensible bands 35, 35, attached to opposite ends of the arcuate surface, extend therealong and are attached to rod 93 to move it, the arrangement being equivalent to a rack and sector free from back lash.

By the arrangement of three circuit closers, in series, one half of a complete revolution of the tire is assured before the beam is arrested at the proper positio no matter which way the beam is first deflected. Assuming that the beam, first swings to the right in Fig. 7, the circuit closer 18 having been left in open position, float switch 30 will be closed by the flow of fluid therethrough, and as the sector 30 moves to the right, pin 33 contacts with arms 13', 19, closing circuit closer I8 and opening circuit closer 19 at the same time so that the circuit to the solenoid is not completed. As the beam starts to the left, the reversal of flow of oil through chamber 80 opens that contact and contactor 19 is closed by weight 13. Circuit closer 13 remains closed. When the beam reaches maximum deflection to the left, fiow of oil in chamber 00 ceases and as the beam starts back the flow of oil reverses closing circuit closer 80 and completing the circuit through the solenoid. This releases lever 63, valve GI is reversed so as to connect pipe 10 to the exhaust and pipe 1| to the air supply, actuating the beam arrest to stop the beam at its position of maximum deflection. At the same time air is supplied to cylinder 0| to reset circuit closer 18 in .open position.

Should the beam move to the left in the first movement, as contactor 10 is open, no closing of the circuit will occur on such first movement. As the beam then starts to the right, the operations described above will follow.

In order to markthe tire at a position opposite to the point where the unbalanced mass may be considered as being concentrated, and to print the tire at this position with a designation of the degree of elf-balance, the following mechanism is provided: A bracket I00 fixed to rails I4, I4, is formed with an arcuate slot I00, concentric with the tire or other article to be tested. To this bracket, a printing device IN is adjustably attached by bolts which enter the arcuate slot. The printing device comprises a pair of headers I02, I03 which support in closely grouped, parallel relation a plurality of air cylinders I04, each of which encloses a piston I05, a rod I06 connected thereto, and a type faced marker I01. The forward ends of the cylinders I04 are all connected through the header I02 in a single flexible tube I00, which communicates, through III, III,

a whistle valve In and a pipe m, with air line 00 so that entrance of compressed air to the cyl- .inders I04 above the pistons is controlled only by the valve Ill. The rear ends of cylinders I04 are connected to individual, flexible tubes each of which is normally connected through an individual valve M2, 2', (see Fig. 13) to the atmosphere through a vent H3 and may, by movement of such to a common air line 4 communicating with pipe 03. Valves H2, H2 are mounted in close arrangement in a valve block or manifold IIS below which all of the valve plungers project. Each valve H2, 2', comprises a cylindrical body, a conical head, and a reduced neck therebetween. Each valve is, held seated in an individual seat in block II5 by an individual coil spring with its conical head shutting off communication between the common air passage 1 I4 and its pipe III, III, and its reduced neck' portion permitting communication between its pipe III, III, and the common passage II3, open to the atmosphere. For compactness the valves are arranged in two rows as shown. The arrangement is such that as each valve is raised against its spring, its stem closes communication between passage II3 and its pipe III, III, and

, opens communication of such pipe to the common air passage II4.

Means are provided for simultaneously operating a plurality of the valves selectively depending upon the mass effecting off-balance of the tire. The selector mechanism is as follows: An air cylinder IIG of the doubleacting type, encloses a piston II1, connected to a piston rod H0, carrying a cross-head H9. Cross head H9 carries a pair of anti-friction rollers I20, I2I. Roller I2I is adapted to support and guide the head along suitable guides I22. The cylinder is mounted on bracket I00. Mounted upon the same bracket is horizontally disposed pin I21. A pair of arms I24, I24 are pivoted at one end on the pin I23, and their free ends support a shaft I25 on which a pair of ratchet wheels I26, I21, are rotatably mounted but fixed to each other.

A pawl I20 pivoted to arm I24 engages ratchet wheel I26 and permits rotation only in a clockwise direction (see Fig. 3). Arms I24, I24 rest on a pin I00 in position to be lifted by contact of roller I20, the arrangement being such that when the cross head is projected away from the cylinder, roller I20 raises arm I24, the ratchet wheel resisting rotation and acting as a cam, and during retroaction of the cross head, roller I20 engages a tooth of ratchet wheel I21 causing rotation thereof without raising arms I24, I24. Arms I24, I24 also support a shaft I23 on which a plurality of arms I30 are pivoted individually. Each arm I30 has one end underlying a valve H2 and its other end supporting a pawl I3I. Arms I30 are guided by a comb I32 fixed to valve body H5, and each pawl is guided through a similar comb I33.

Fixed to the beam of the device are a plurality of sectors I34, each of which is directly above a pawl I3I. The arcuate edges of these sectors are formed with teeth I34 with intervening or flanking spaces. If one of the pawls I3I engages the top of a tooth I34 when arm I24 is raised, its opposite end will raise a corresponding valve II2 admitting air to its corresponding cylinder I04 and causing the type fitted plunger I01 to be projected against the article being tested. If, however, the pawl fails to be below a tooth valve, be connected Ill when arm I is raised the corresponding valve will not be operated.

Sectors I have their teeth so arranged that a single tooth on one is over the pawl when the beam deflection is that due to one inch-ounce of unbalanced mass, a single tooth on another corresponds to two inch ounces deflection, etc. An other sector has a tooth for each half inch ounce position with spaces therebetween. Still another sector has teeth corresponding to each odd fractionah deflection by one-quarter inch ounce. The pistons III! are equipped with corresponding ype numerals.

Inorder to retract the type plungers I01, valve IIII, previously described, is so mounted upon bracket IIIII that when cross-head H9 is advanced to its limit it contacts with the whistle valve plunger admitting air simultaneously to the cylinders I at their forward ends.

Cylinder H6 is operated as follows: A pipe I3! is connected to the rear end of the cylinder and supplies air from pipe II so that cross-head II! is projected simultaneous with arrest of the .beam. This assures printing of the off balance mass on the article being tested when the beam is at rest at the position of greatest deflection. A. pipe I 36 connects the forward end of cylinder IIi to pipe III so that retraction of cross-head II! is simultaneous with release of the beam.

Means are provided for inking the type faces of the printing plungers as follows: An inking roller I is rotatably mounted in a carriage I4I adapted to slide upon rails I42. Pinions I43, I43 fixed to the ink rollengage racks I44, I44 mounted along the rails I42 and insure rotation of the ink roll as it passes over the type. A cylinder I45 mounted upon bracket IIII encloses a piston I46 connected to carriage Ill by a piston rod I". A pipe I48 connects the forward end of the cylinder to air line 69, so that this end of the cylinder is always under pressure. A pipe. I" connects the rear end of the cylinder through a whistle valve I50 to air line 69. Due to diil'erence in area of the two sides of the piston, the piston rod being large as compared to thecylinder bore, when air is admitted to both sides of the piston, the unbalanced pressure advances the piston causing the ink roller to pass over the type. The whistle valve I50 is located beneath the lever 63 so that when the treadle 63' is depressed it momentarily opens the whistle valve and advances the ink roller over the type. When the operators foot is removed lever 63 raises until it contacts with roller 16, but this is sufllcient to close the whistle valve and the inking mechanism is then retracted.

In the operation of the machine with the beam arrested and the article supporting spindle rotating at a very slow velocity, preferably about 6 R'. P. M., a tire or other article to be balanced is placed on the chuck 25. Treadle 63* is then depressed momentarily causing the ink roll to apply ink to the type, retracting the cross head I I 9, and simultaneously releasing the beam. The latch H locks the treadle lever 63 in this position and the beam proceeds to oscillate with the tire or other article rotating at a constant velocity. When the maximum point'of deflection of the beam is attained the closing of the electric contacts, as heretofore described, actuates the solenoid I1 and spring I2 raises the treadle lever. This causes immediate arrest of the beam and simultaneous advance of the cross-head I I9, thereby opening certain of the valves II2 as determined by the amount of deflection of the beam. The marking plungers are projected against the tire or other object and are immediately retracted as the cross head H9 opens the valve I08. As the cross head H9 is advanced, the contactor I8 is automatically reset .for the next article to be tested.

I claim:

1. Apparatus for determining the characteristics of an unbalanced force affecting balance of a rotatable object-about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on an axis coincident with the axis of oscillation of the beam, means including an element attached to the beam for indicating the deflection of the'beam due to the unbalancedforce, and means actuated by movement of said element for arresting the beam at its deflected position.

2. Apparatus for determining the characteristics of an unbalanced force affecting balance of a rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on an axis parallel to and in the vertical plane of the fulcrum of the beam at a uniform velocity, means including an element attached to the beam for indicating the deflection of the beam due to the unbalanced force, and means actuated by movement of said element for automatically arresting the beam at its deflected position.

3. Apparatus for determining the characteristics of an unbalanced force affecting the balance of a rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on an axis coincident with the axis of oscillation of the beam at a uniform velocity, means including an element attached to said beam for indicating the deflection of the beam due to the unbalanced force, and means actuated by movement of said element for automatically arresting the beam at its deflected position.

4. Apparatus for determining the characteristics of an unbalanced force ail'ecting balance of a. rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on its axis, means including an element attached to said beam for indicating the deflection of the beam due to theunbalanced force, means actuated by movement of said element for automatically arresting the beam at its deflected position,

and means also actuated by movement of said element for automatically marking the object to indicate the position where added mass is required to balance the object.

5. Apparatus for determining the characteristics of an unbalanced force affecting balance of a rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on an axis coincident with the axis of oscillation of the beam, means including an element attached to said beam for indicating the deflectionof the beam due to the unbalanced force, and means actuated by movement of said element for automatically marking the object to indicate the position where added mass is required to balance the object.

6. Apparatus for determining the characteristics of an unbalanced force affecting the balance of a rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on an axis coincident with the axis of oscillation of the beam at a uniform velocity, means including an element attached to said beam for indicating the deflection of the beam due to the unbalanced force, means actuated by movement of said element for automatically arresting the beam at its deflected position, and means also actuated by movement of said element for automatically marking the object to indicate the position where added mass is required to balance the object.

'7. Apparatus for determining the characteristics of an unbalanced force affecting balance of a rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on its axis, means including an element attached to said beam for indicating the deflection of the beam due to the unbalanced force, means actuated by movement of said element for automatically arresting the beam at its deflected position, means also actuated by movement of said element and controlled by the amount of deflection of said beam for automatically marking the object to indicate the position where added mass is required to balance the object and the amount of such mass.

8. Apparatus for determining the characteristics of an unbalanced force affecting balance of a rotatable object about its axis, said apparatus comprising a balanced beam, means carried thereby for supporting and rotating the object on an axis coincident with the axis of oscillation of the beam, means including an element attached to said beam for indicating the deflection of the beam due to the unbalanced force, means actuated by movement of said element and controlled by the amount of deflection thereof for automatically marking the object to indicate the position where added mass is required to balance the object and the amount of such mass.

9. Apparatus for determining the characteristics of an unbalanced force affecting the balance of a rotatable object about its axis, said apparatus comprising a balance beam, means carried thereby for supporting and rotating the object on an axis coincident with the axis of oscillation of the beam at a uniform velocity, means including an element attached to said beam for indicating the deflection of the beam due to the unbalanced force, means actuated'by movement of said element for automatically arresting the beam at its deflected position, means also actuated by movement of said element and controlled by theamount of deflection thereof for automatically marking the object to indicate the position where added mass is required to balance the object and the amount of such mass.

10. Balancing apparatus comprising a balance beam supported for response to the unbalanced force of an oil-balance article rotatably associated therewith, means for indicating the deflection'of the beam, and means controlled by the swing of the beam for automatically arresting the beam at a determinate position in its deflection.

ll. Balancing apparatus comprising a balance beam structure responsive to the unbalanced force of an off-balance article rotatably associated therewith, a support for the beam structure including a fulcrum and bearing and means for arresting the beam structure at varying positions in its deflection, said means comprising a stopping surface and means controlled by the swing of the beam structure for automatically separating the fulcrum from its bearing and engaging a part of the beam structure with the stopping surface.

12. Balancing apparatus comprising a balance beam, means including a fulcrum and bearing therefor for supporting the beam, and means controlled by the swing of the beam for automatically separating the fulcrum from its bearing at a determinate position in the swing of the beam.

13. Balancing apparatus comprising a balancing device responsive to the unbalanced force of an off-balance article rotatably associated therewith, means for rotatably supporting an article for such response, and means controlled by the balancing device for automatically marking the article to indicate its position of off-balance and the amount thereof.

14. Balancing apparatus comprising a balancing device responsive to the unbalanced force of an oft-balance article associated therewith, means for rotatably supporting an article for such response, means for indicating the amount of ofibalance of the article, means controlled by the balancing device for arresting the indicating means at the position of maximum deflection thereof, and means for automatically delaying the operation of the arresting device until the object has rotated at least one-half revolution.

15. Balancing apparatus comprising a balancing device responsive to the unbalanced force of an off-balance article rotatably associated therewith, means controlled by the balancing device for automatically registering the amount of off-balance of the article, and means also controlled by the balancing device for automatically marking the article to indicate thereon the amount of oilbalance thus registered and the position thereof on the article.

16. Balancing apparatus comprising a balancing device responsive to the unbalanced force of an off-balance article rotatably associated therewith, means for rotatably supporting an article for such response, a plurality of movable printing elements for marking on the article the amount of .ofl-balance, and selector means controlled by the deflection of the balancing device for selectively moving said printing elements to the article to mark the same with the amount of off-balance.

CHARLES C. CADDEN. 

